gecko-dev/dom/events/WheelHandlingHelper.cpp
Nicholas Nethercote b71747b2ac Bug 1299727 - Rename NS_WARN_IF_FALSE as NS_WARNING_ASSERTION. r=erahm.
The new name makes the sense of the condition much clearer. E.g. compare:

  NS_WARN_IF_FALSE(!rv.Failed());

with:

  NS_WARNING_ASSERTION(!rv.Failed());

The new name also makes it clearer that it only has effect in debug builds,
because that's standard for assertions.

--HG--
extra : rebase_source : 886e57a9e433e0cb6ed635cc075b34b7ebf81853
2016-09-01 15:01:16 +10:00

552 lines
17 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "WheelHandlingHelper.h"
#include "mozilla/EventDispatcher.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/Preferences.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsIContent.h"
#include "nsIDocument.h"
#include "nsIPresShell.h"
#include "nsIScrollableFrame.h"
#include "nsITimer.h"
#include "nsPluginFrame.h"
#include "nsPresContext.h"
#include "prtime.h"
#include "Units.h"
#include "AsyncScrollBase.h"
namespace mozilla {
/******************************************************************/
/* mozilla::DeltaValues */
/******************************************************************/
DeltaValues::DeltaValues(WidgetWheelEvent* aEvent)
: deltaX(aEvent->mDeltaX)
, deltaY(aEvent->mDeltaY)
{
}
/******************************************************************/
/* mozilla::WheelHandlingUtils */
/******************************************************************/
/* static */ bool
WheelHandlingUtils::CanScrollInRange(nscoord aMin, nscoord aValue, nscoord aMax,
double aDirection)
{
return aDirection > 0.0 ? aValue < static_cast<double>(aMax) :
static_cast<double>(aMin) < aValue;
}
/* static */ bool
WheelHandlingUtils::CanScrollOn(nsIFrame* aFrame,
double aDirectionX, double aDirectionY)
{
nsIScrollableFrame* scrollableFrame = do_QueryFrame(aFrame);
if (scrollableFrame) {
return CanScrollOn(scrollableFrame, aDirectionX, aDirectionY);
}
nsPluginFrame* pluginFrame = do_QueryFrame(aFrame);
return pluginFrame && pluginFrame->WantsToHandleWheelEventAsDefaultAction();
}
/* static */ bool
WheelHandlingUtils::CanScrollOn(nsIScrollableFrame* aScrollFrame,
double aDirectionX, double aDirectionY)
{
MOZ_ASSERT(aScrollFrame);
NS_ASSERTION(aDirectionX || aDirectionY,
"One of the delta values must be non-zero at least");
nsPoint scrollPt = aScrollFrame->GetScrollPosition();
nsRect scrollRange = aScrollFrame->GetScrollRange();
uint32_t directions = aScrollFrame->GetPerceivedScrollingDirections();
return (aDirectionX && (directions & nsIScrollableFrame::HORIZONTAL) &&
CanScrollInRange(scrollRange.x, scrollPt.x,
scrollRange.XMost(), aDirectionX)) ||
(aDirectionY && (directions & nsIScrollableFrame::VERTICAL) &&
CanScrollInRange(scrollRange.y, scrollPt.y,
scrollRange.YMost(), aDirectionY));
}
/******************************************************************/
/* mozilla::WheelTransaction */
/******************************************************************/
nsWeakFrame WheelTransaction::sTargetFrame(nullptr);
uint32_t WheelTransaction::sTime = 0;
uint32_t WheelTransaction::sMouseMoved = 0;
nsITimer* WheelTransaction::sTimer = nullptr;
int32_t WheelTransaction::sScrollSeriesCounter = 0;
bool WheelTransaction::sOwnScrollbars = false;
/* static */ bool
WheelTransaction::OutOfTime(uint32_t aBaseTime, uint32_t aThreshold)
{
uint32_t now = PR_IntervalToMilliseconds(PR_IntervalNow());
return (now - aBaseTime > aThreshold);
}
/* static */ void
WheelTransaction::OwnScrollbars(bool aOwn)
{
sOwnScrollbars = aOwn;
}
/* static */ void
WheelTransaction::BeginTransaction(nsIFrame* aTargetFrame,
WidgetWheelEvent* aEvent)
{
NS_ASSERTION(!sTargetFrame, "previous transaction is not finished!");
MOZ_ASSERT(aEvent->mMessage == eWheel,
"Transaction must be started with a wheel event");
ScrollbarsForWheel::OwnWheelTransaction(false);
sTargetFrame = aTargetFrame;
sScrollSeriesCounter = 0;
if (!UpdateTransaction(aEvent)) {
NS_ERROR("BeginTransaction is called even cannot scroll the frame");
EndTransaction();
}
}
/* static */ bool
WheelTransaction::UpdateTransaction(WidgetWheelEvent* aEvent)
{
nsIFrame* scrollToFrame = GetTargetFrame();
nsIScrollableFrame* scrollableFrame = scrollToFrame->GetScrollTargetFrame();
if (scrollableFrame) {
scrollToFrame = do_QueryFrame(scrollableFrame);
}
if (!WheelHandlingUtils::CanScrollOn(scrollToFrame,
aEvent->mDeltaX, aEvent->mDeltaY)) {
OnFailToScrollTarget();
// We should not modify the transaction state when the view will not be
// scrolled actually.
return false;
}
SetTimeout();
if (sScrollSeriesCounter != 0 && OutOfTime(sTime, kScrollSeriesTimeoutMs)) {
sScrollSeriesCounter = 0;
}
sScrollSeriesCounter++;
// We should use current time instead of WidgetEvent.time.
// 1. Some events doesn't have the correct creation time.
// 2. If the computer runs slowly by other processes eating the CPU resource,
// the event creation time doesn't keep real time.
sTime = PR_IntervalToMilliseconds(PR_IntervalNow());
sMouseMoved = 0;
return true;
}
/* static */ void
WheelTransaction::MayEndTransaction()
{
if (!sOwnScrollbars && ScrollbarsForWheel::IsActive()) {
ScrollbarsForWheel::OwnWheelTransaction(true);
} else {
EndTransaction();
}
}
/* static */ void
WheelTransaction::EndTransaction()
{
if (sTimer) {
sTimer->Cancel();
}
sTargetFrame = nullptr;
sScrollSeriesCounter = 0;
if (sOwnScrollbars) {
sOwnScrollbars = false;
ScrollbarsForWheel::OwnWheelTransaction(false);
ScrollbarsForWheel::Inactivate();
}
}
/* static */ bool
WheelTransaction::WillHandleDefaultAction(WidgetWheelEvent* aWheelEvent,
nsWeakFrame& aTargetWeakFrame)
{
nsIFrame* lastTargetFrame = GetTargetFrame();
if (!lastTargetFrame) {
BeginTransaction(aTargetWeakFrame.GetFrame(), aWheelEvent);
} else if (lastTargetFrame != aTargetWeakFrame.GetFrame()) {
EndTransaction();
BeginTransaction(aTargetWeakFrame.GetFrame(), aWheelEvent);
} else {
UpdateTransaction(aWheelEvent);
}
// When the wheel event will not be handled with any frames,
// UpdateTransaction() fires MozMouseScrollFailed event which is for
// automated testing. In the event handler, the target frame might be
// destroyed. Then, the caller shouldn't try to handle the default action.
if (!aTargetWeakFrame.IsAlive()) {
EndTransaction();
return false;
}
return true;
}
/* static */ void
WheelTransaction::OnEvent(WidgetEvent* aEvent)
{
if (!sTargetFrame) {
return;
}
if (OutOfTime(sTime, GetTimeoutTime())) {
// Even if the scroll event which is handled after timeout, but onTimeout
// was not fired by timer, then the scroll event will scroll old frame,
// therefore, we should call OnTimeout here and ensure to finish the old
// transaction.
OnTimeout(nullptr, nullptr);
return;
}
switch (aEvent->mMessage) {
case eWheel:
if (sMouseMoved != 0 &&
OutOfTime(sMouseMoved, GetIgnoreMoveDelayTime())) {
// Terminate the current mousewheel transaction if the mouse moved more
// than ignoremovedelay milliseconds ago
EndTransaction();
}
return;
case eMouseMove:
case eDragOver: {
WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
if (mouseEvent->IsReal()) {
// If the cursor is moving to be outside the frame,
// terminate the scrollwheel transaction.
nsIntPoint pt = GetScreenPoint(mouseEvent);
nsIntRect r = sTargetFrame->GetScreenRect();
if (!r.Contains(pt)) {
EndTransaction();
return;
}
// If the cursor is moving inside the frame, and it is less than
// ignoremovedelay milliseconds since the last scroll operation, ignore
// the mouse move; otherwise, record the current mouse move time to be
// checked later
if (!sMouseMoved && OutOfTime(sTime, GetIgnoreMoveDelayTime())) {
sMouseMoved = PR_IntervalToMilliseconds(PR_IntervalNow());
}
}
return;
}
case eKeyPress:
case eKeyUp:
case eKeyDown:
case eMouseUp:
case eMouseDown:
case eMouseDoubleClick:
case eMouseClick:
case eContextMenu:
case eDrop:
EndTransaction();
return;
default:
break;
}
}
/* static */ void
WheelTransaction::Shutdown()
{
NS_IF_RELEASE(sTimer);
}
/* static */ void
WheelTransaction::OnFailToScrollTarget()
{
NS_PRECONDITION(sTargetFrame, "We don't have mouse scrolling transaction");
if (Preferences::GetBool("test.mousescroll", false)) {
// This event is used for automated tests, see bug 442774.
nsContentUtils::DispatchTrustedEvent(
sTargetFrame->GetContent()->OwnerDoc(),
sTargetFrame->GetContent(),
NS_LITERAL_STRING("MozMouseScrollFailed"),
true, true);
}
// The target frame might be destroyed in the event handler, at that time,
// we need to finish the current transaction
if (!sTargetFrame) {
EndTransaction();
}
}
/* static */ void
WheelTransaction::OnTimeout(nsITimer* aTimer, void* aClosure)
{
if (!sTargetFrame) {
// The transaction target was destroyed already
EndTransaction();
return;
}
// Store the sTargetFrame, the variable becomes null in EndTransaction.
nsIFrame* frame = sTargetFrame;
// We need to finish current transaction before DOM event firing. Because
// the next DOM event might create strange situation for us.
MayEndTransaction();
if (Preferences::GetBool("test.mousescroll", false)) {
// This event is used for automated tests, see bug 442774.
nsContentUtils::DispatchTrustedEvent(
frame->GetContent()->OwnerDoc(),
frame->GetContent(),
NS_LITERAL_STRING("MozMouseScrollTransactionTimeout"),
true, true);
}
}
/* static */ void
WheelTransaction::SetTimeout()
{
if (!sTimer) {
nsCOMPtr<nsITimer> timer = do_CreateInstance(NS_TIMER_CONTRACTID);
if (!timer) {
return;
}
timer.swap(sTimer);
}
sTimer->Cancel();
DebugOnly<nsresult> rv =
sTimer->InitWithFuncCallback(OnTimeout, nullptr, GetTimeoutTime(),
nsITimer::TYPE_ONE_SHOT);
NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
"nsITimer::InitWithFuncCallback failed");
}
/* static */ nsIntPoint
WheelTransaction::GetScreenPoint(WidgetGUIEvent* aEvent)
{
NS_ASSERTION(aEvent, "aEvent is null");
NS_ASSERTION(aEvent->mWidget, "aEvent-mWidget is null");
return (aEvent->mRefPoint + aEvent->mWidget->WidgetToScreenOffset())
.ToUnknownPoint();
}
/* static */ uint32_t
WheelTransaction::GetTimeoutTime()
{
return Preferences::GetUint("mousewheel.transaction.timeout", 1500);
}
/* static */ uint32_t
WheelTransaction::GetIgnoreMoveDelayTime()
{
return Preferences::GetUint("mousewheel.transaction.ignoremovedelay", 100);
}
/* static */ DeltaValues
WheelTransaction::AccelerateWheelDelta(WidgetWheelEvent* aEvent,
bool aAllowScrollSpeedOverride)
{
DeltaValues result(aEvent);
// Don't accelerate the delta values if the event isn't line scrolling.
if (aEvent->mDeltaMode != nsIDOMWheelEvent::DOM_DELTA_LINE) {
return result;
}
if (aAllowScrollSpeedOverride) {
result = OverrideSystemScrollSpeed(aEvent);
}
// Accelerate by the sScrollSeriesCounter
int32_t start = GetAccelerationStart();
if (start >= 0 && sScrollSeriesCounter >= start) {
int32_t factor = GetAccelerationFactor();
if (factor > 0) {
result.deltaX = ComputeAcceleratedWheelDelta(result.deltaX, factor);
result.deltaY = ComputeAcceleratedWheelDelta(result.deltaY, factor);
}
}
return result;
}
/* static */ double
WheelTransaction::ComputeAcceleratedWheelDelta(double aDelta, int32_t aFactor)
{
return mozilla::ComputeAcceleratedWheelDelta(aDelta, sScrollSeriesCounter, aFactor);
}
/* static */ int32_t
WheelTransaction::GetAccelerationStart()
{
return Preferences::GetInt("mousewheel.acceleration.start", -1);
}
/* static */ int32_t
WheelTransaction::GetAccelerationFactor()
{
return Preferences::GetInt("mousewheel.acceleration.factor", -1);
}
/* static */ DeltaValues
WheelTransaction::OverrideSystemScrollSpeed(WidgetWheelEvent* aEvent)
{
MOZ_ASSERT(sTargetFrame, "We don't have mouse scrolling transaction");
MOZ_ASSERT(aEvent->mDeltaMode == nsIDOMWheelEvent::DOM_DELTA_LINE);
// If the event doesn't scroll to both X and Y, we don't need to do anything
// here.
if (!aEvent->mDeltaX && !aEvent->mDeltaY) {
return DeltaValues(aEvent);
}
return DeltaValues(aEvent->OverriddenDeltaX(),
aEvent->OverriddenDeltaY());
}
/******************************************************************/
/* mozilla::ScrollbarsForWheel */
/******************************************************************/
const DeltaValues ScrollbarsForWheel::directions[kNumberOfTargets] = {
DeltaValues(-1, 0), DeltaValues(+1, 0), DeltaValues(0, -1), DeltaValues(0, +1)
};
nsWeakFrame ScrollbarsForWheel::sActiveOwner = nullptr;
nsWeakFrame ScrollbarsForWheel::sActivatedScrollTargets[kNumberOfTargets] = {
nullptr, nullptr, nullptr, nullptr
};
bool ScrollbarsForWheel::sHadWheelStart = false;
bool ScrollbarsForWheel::sOwnWheelTransaction = false;
/* static */ void
ScrollbarsForWheel::PrepareToScrollText(EventStateManager* aESM,
nsIFrame* aTargetFrame,
WidgetWheelEvent* aEvent)
{
if (aEvent->mMessage == eWheelOperationStart) {
WheelTransaction::OwnScrollbars(false);
if (!IsActive()) {
TemporarilyActivateAllPossibleScrollTargets(aESM, aTargetFrame, aEvent);
sHadWheelStart = true;
}
} else {
DeactivateAllTemporarilyActivatedScrollTargets();
}
}
/* static */ void
ScrollbarsForWheel::SetActiveScrollTarget(nsIScrollableFrame* aScrollTarget)
{
if (!sHadWheelStart) {
return;
}
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(aScrollTarget);
if (!scrollbarMediator) {
return;
}
sHadWheelStart = false;
sActiveOwner = do_QueryFrame(aScrollTarget);
scrollbarMediator->ScrollbarActivityStarted();
}
/* static */ void
ScrollbarsForWheel::MayInactivate()
{
if (!sOwnWheelTransaction && WheelTransaction::GetTargetFrame()) {
WheelTransaction::OwnScrollbars(true);
} else {
Inactivate();
}
}
/* static */ void
ScrollbarsForWheel::Inactivate()
{
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(sActiveOwner);
if (scrollbarMediator) {
scrollbarMediator->ScrollbarActivityStopped();
}
sActiveOwner = nullptr;
DeactivateAllTemporarilyActivatedScrollTargets();
if (sOwnWheelTransaction) {
sOwnWheelTransaction = false;
WheelTransaction::OwnScrollbars(false);
WheelTransaction::EndTransaction();
}
}
/* static */ bool
ScrollbarsForWheel::IsActive()
{
if (sActiveOwner) {
return true;
}
for (size_t i = 0; i < kNumberOfTargets; ++i) {
if (sActivatedScrollTargets[i]) {
return true;
}
}
return false;
}
/* static */ void
ScrollbarsForWheel::OwnWheelTransaction(bool aOwn)
{
sOwnWheelTransaction = aOwn;
}
/* static */ void
ScrollbarsForWheel::TemporarilyActivateAllPossibleScrollTargets(
EventStateManager* aESM,
nsIFrame* aTargetFrame,
WidgetWheelEvent* aEvent)
{
for (size_t i = 0; i < kNumberOfTargets; i++) {
const DeltaValues *dir = &directions[i];
nsWeakFrame* scrollTarget = &sActivatedScrollTargets[i];
MOZ_ASSERT(!*scrollTarget, "scroll target still temporarily activated!");
nsIScrollableFrame* target = do_QueryFrame(
aESM->ComputeScrollTarget(aTargetFrame, dir->deltaX, dir->deltaY, aEvent,
EventStateManager::COMPUTE_DEFAULT_ACTION_TARGET));
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(target);
if (scrollbarMediator) {
nsIFrame* targetFrame = do_QueryFrame(target);
*scrollTarget = targetFrame;
scrollbarMediator->ScrollbarActivityStarted();
}
}
}
/* static */ void
ScrollbarsForWheel::DeactivateAllTemporarilyActivatedScrollTargets()
{
for (size_t i = 0; i < kNumberOfTargets; i++) {
nsWeakFrame* scrollTarget = &sActivatedScrollTargets[i];
if (*scrollTarget) {
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(*scrollTarget);
if (scrollbarMediator) {
scrollbarMediator->ScrollbarActivityStopped();
}
*scrollTarget = nullptr;
}
}
}
} // namespace mozilla